1. Field of the Invention
This invention relates to detergent compositions containing novel builders, to a method for making such builders, and to detergent compositions containing such builders.
2. Description of the Prior Art
Because phosphates are believed to contribute to the eutrophication of waters, considerable research efforts recently have been expended with a view of providing builders which are phosphorus free.
Phosphate-free organic builders are already known and some are disclosed in Unilever Netherlands patent application 72-06772 and in U.S. Pat. No. 3,635,830. The first of these discloses the tetrahydrate and pentahydrate of carboxymethoxysuccinate trisodium which were used separately or together as builders in detergent compositions. Undesirably, these compounds have to be treated with water-ethanol to hydrate them sufficiently to be easily handled thereby adding considerably to production costs. For its part, U.S. Pat. No. 3,635,830 discloses, as builders, salts of oxydisuccinic acid, carboxymethyloxy succinic acid and hydrofuran tetracarboxylic acid. The recited compounds required several purification steps before incorporation in detergent compositions.